radarthe brochure says:
I/J (X) band active phased array for low elevation detection out to 75 km
which does not mean that apar is able to detect a sea skimming target at 75 km. low elevation is not the same than low altitude.
the reason that x-band is preferable for low elevation horizon search is that the first lobe is very close to the surface compared to lower frequencies.
radartop right is a rnzn protector class opv.
for the last one i pass. most likely a service craft or a small patrol craft but a small landing craft is also possible.
radarany information on when the i-mast will be installed and why it has not be done earlier?
radarThe message that the SM-3 ASAT shot, very clearly, gave out was of the pointlessness of trying to target USN warships from LEO satellite platforms. Very little need to shoot down the missiles when you can poke out the eyes of the sighting system!.
the satellite back in 2008 was shot down at an altitude of 240 km. does this proof that they can handle a satellite at 500 km (e.g. sar-lupe) or 700 km (lacrosse) or 1100 km (yaogan 9 series)? i’m not sure.
afaik the chinese asat-systems are based on a df-21 missile which is significant bigger than sm-3. for the chinese systems engagement altitudes of 600, 800 and 1000+ km (depending on asat type and source).
radarThat quote came from a prolonged discussion with an ex-Marconi guy who had been intimitely familiar with GWS25. The conversation came about regarding ICWI with mechanical director elements. He stated that it was a non-starter and the claims that were just being made for area capability off ESSM were hinged on CEA’s X-band director AND ICWI (my mistake there earlier I misunderstood what he was saying!). He was saying that the testing undertaken on Arunta had simulated ICWI operation and a modicum of local area defence capability.
sorry jonesy but all this doesn’t sound reasonable to me. icwi was developed to be used with electronically scanned array (able to generate several hundred to more then thousand pencil beams per face and second). i think there is no public number on how often a target is illuminated per second while using icwi. (imho the best implementation of icwi should allow to adapt these parameters to the target performance). anyhow during icwi a target is illuminated several times per second.
the ran might have tested the essm in a icwi mode (e.g. just by switching the cw-illuminator on and off) but if they used the same mechanically steered illuminator for the test which normally provides cwi for essm or sea sparrow and if your statement is right that these systems are not able to keep a crossing target on the beam how could this test work? in this case icwi only makes a bad thing worse. i think it’s unlikely that a mechanically steered system is able to realign to the target in milliseconds after the target left the beam.
imho they used cwi during the live firing trials onboard of the hmas warramunga (not the arunta). it’s useless to simulate icwi if the problem is not the illumination but the mechanical steering.
from my understanding icwi is more or less a software update on the missile side. if true, it should be no problem to use essm’s with cwi in crossing-target engagements simply by a new software.
radarThe RAN did do local area defence testing with ESSM as part of the same trials that ICWI was tested in. It was the ICWI technology that was the enabler for the crossing target trials. The CEA active scan director with its ability to hand off the beam between faces, to obviate any array masking issues, will improve that further.
i’m a little bit confused now because these tests were done back in 2003. any source they used icwi during these tests?
btw while searching sources i run over this:
Now, for an area missile like SM-2 dealing with crossing threats 70km off isnt such a problem, this is because the target box can be predicted and the missile mcg’d into it to allow for terminal phase lockup. Not easy, but, not…erm…rocket science. Now close that in to 15km range and the time-to-intercept counter dont look so good. I know ESSM can do crossing engagements but it uses a seperate Homing All The Way mode (not the ICWI one) tying down a fire channel for the whole engagement cycle. If you only start with four fire channels on your APAR array and are in the process of engaging more distant contacts…..well…..it might be unfortunate!.
written by you in 2006.
as sayed before shooting at crossing targets imho is not enabled by either icwi nor by cwi and also not by active seekers. the missile performance is critical, supported by optimized flight path and data links.
if shooting at a crossing target is that difficult with a semi active seeker, we have to ask why the us-navy and so many other navies don’t use active radar homing.
btw. does anybody know the range of a aster or mica seeker against a low rcs ashm and if artisan is able to provide a data uplink? (rpm?)
radari don’t think, that keeping a crossing target in the beam is a big deal with modern fire control systems. otherwise all radar controlled pdms and ciws are useless as soon as an inbound target starts maneuvering or using a pop up maneuver.
afaik the ran successful did some crossing targets tests with essm some time ago. (with a mechanically steered illuminator of course).
radarNope. Semi active systems can be saturated much easier and are much more sensitive to battle damage when the directors are down.
i think you missed the point. the graph and my comment is about bearing rate changes on crossing targets and not about saturation or battle damage. 😉
radara mach 2 target passing at 12 km will result in a angle change rate of 3.2 °/sec max (at closest point). it’s unclear to me why this is a big challenge for the fire control system. imho in this case the sam missile parameter are much more critical than the seeker homing mode.
radarGermany did try building its own 155 mm gun. Unable to do it, they chose the 127 mm Oto. Had the 155 TMF been available in time, it would have won.
i wouldn’t say the german were not able to build it but their idea didn’t work. the idea was to navalize a pzh 2000 turret with minimal effort. but then they realised that this “cheap” solution would not work and that such a 155 mm gun would cost much more money than expected.
so they lost the interest on it.
in addition to this it’s also questionable for which reason the german navy needs such a gun (no marines, landing crafts etc.). imho the 127/64 gun is a good choice (low risk, common standard with upgrade path for the future, …)
and buying the italian oto melaras 127/64 is a good compensation for the u-212 deal.
radaryes jonsey, i take it very literally. i want to show that the correct comparison is not apar vs sampson but apar+smart-l vs. sampson+s1850m.
and afaik x-band has a superior low altitude detection range because of the propagation effects but maybe i’m wrong. of course other typical x-band characteristics like a very wide frequency bandwidth and a small beamwidth also helps a lot.
radari think it’s not true that sampson can act as a long range vsr and as a mfr at the same time. sampson is able to do both, thats no question but if for example it is used in a long range volume search mode the performance of all the mfr tasks is greatly reduced.
thats a common position.
e.g. http://navy-matters.beedall.com/sampson.htm
BAE Systems have also claimed that Sampson eliminates the need for several separate systems. They suggest that on the Type 45 destroyer, the Alenia Marconi Systems/Signaal S 1850M long-range 3D radar that is designed to work in partnership with Sampson “really is superfluous and is not needed to perform the mission of the ship”. BAE Systems believes that the reason the large volume search radar has been incorporated in to PAAMS is “more of a historic nature, associated with [the] work sharing issues” that were a huge problem during the trilateral Project Horizon
This claim is rather an over simplification. Some tasks are difficult to combine, for example (long range) volume search takes a lot of radar resources, leaving little room for other tasks such as targeting. Combining volume search with other tasks also results either in slow search rates or in low overall quality per task. Driving parameters in radar performance is time-on-target or observation time per beam. This is perhaps a the key reason why the Royal Navy selected the S1850M Long Range Radar to complement Sampson on the Type 45 destroyers. It is also a reason why NATO in its NATO Anti-Air Warfare System study (NAAWS) defined the preferred AAW system as consisting of a complementary Volume Search Radar and MFR. This – as NATO points out – gives the added advantage that the two systems can use two different radar frequencies; one being a good choice for long range search, the other a good choice for an MFR (which is especially nice as physics makes both tasks difficult to combine).
i don’t think that the s1850m can really act as a backup for sampson because there is no chance to control a aster with it. so if apar/sampson fails both ship-types are toothless. if the smart-l/s1850m fails, the type 45 are in a better position than the apar-equipped ships.
btw. from my understanding x-band is preferable in terms of horizon search. sampson can gain some extra height but s-band is not the best choice for doing a horizon scan.
radarAegis wasn’t originally available for NATO. APAR didn’t meet UK requirements (but was a lot cheaper), hence the need for SAMPSON and SMART-L.
which requirement is not met by apar+smart-l?
radarSimple answer is that we needed more capability than AEGIS/SPY-1/SM2 offered when the competition was run.
other participants from the nfr-90 decided to develop apar. so there were other paths out than only aegis for naaws.
radarInterestingly, while both F124 and LCF use Tacticos, the latter has not experienced the problem the former has.
imho both systems are not identical.
the information around are very strange. afaik there are some documents around (even some labeled with thales) which says, that both uses tacticos. but on the other hand a lot of sources are quoting sewaco-XI for lcf and sewaco-fd/tacticos for the f-124.
the f-124 cms is often quoted to be more advanced than the cms of the lcf and to support this claim the doctrine based automation of the f-124 cms is used as example.
to me it’s unclear how big the differences are (only software or software and system architecture) but it seems to be clear that they use not the same systems because in this case there is no reason what may caused the big trouble with the f-124 cms.
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